Liquid crystal display including source lines defining an opening portion and a defect correcting method for the same

ABSTRACT

A liquid crystal display uses a pixel division method by which the size of a defect can be reduced much more than conventionally possible, and a defect correcting method for the liquid crystal display. The liquid crystal display is provided with an active matrix array substrate including a plurality of gate lines and a plurality of source lines arranged on a transparent substrate to intersect with each other, and a plurality of pixel electrodes arranged in a matrix, each pixel electrode including an assembly of a plurality of sub-pixel electrodes, separate TFTs respectively connected to the sub-pixel electrodes in the vicinity of an intersection portion of the gate line and the source line, the TFTs being driven by the common gate line and the common source line, and at least one opening portion being formed in a lower-layer side line placed in a lower layer at the intersection portion.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a liquid crystal display and a defectcorrecting method for the same, and more specifically relates to aliquid crystal display adopting a pixel division method and a defectcorrecting method for the same.

2. Description of the Related Art

A liquid crystal display has excellent characteristics such as highdefinition, thinness, lightness and low power consumption. Thus,recently, the liquid crystal display is rapidly expanding its market inaccordance with an improvement in production capacity, an improvement inprice competition with other displays, and the like.

For this kind of liquid crystal display, Japanese Patent ApplicationUnexamined Publication No. 2004-78157, for example, discloses a liquidcrystal display provided with an active matrix array substrate adoptinga pixel division method in which each pixel electrode includes anassembly of a plurality of sub-pixel electrodes.

FIG. 13 is a schematic diagram showing a pixel electrode formed on anactive matrix array substrate provided in a conventional liquid crystaldisplay. Specifically, as shown in FIG. 13, a pixel electrode 101 on anactive matrix array substrate 100 is split into sub-pixel electrodes 103a and 103 b interposing a gate line 102 therebetween. In the vicinity ofan intersection portion 105 of the gate line 102 and a source line 104,separate thin film transistors (TFTs) 106 a and 106 b which are drivenby the common gate line 102 and the common source line 104 are provided,and the TFTs 106 a and 106 b are electrically connected to theircorresponding sub-pixel electrodes 103 a and 103 b.

In the liquid crystal display provided with the above-mentioned activematrix array substrate 100, the common gate line 102 and the commonsource line 104 are used to drive the sub-pixel electrodes 103 a and 103b via the separate TFTs 106 a and 106 b.

Therefore, for example, as shown in FIG. 14, when a leak 107 a(hereinafter referred to as the “SG leak”) is developed in the TFT 106 abetween the gate line 102 and the source line 104, and a correction forthe SG leak 107 a is performed using a correcting device such as alaser, it is necessary to cut the source line 104 at cut sections 108 aand 108 b to completely isolate the SG leak 107 a from the source line104. Consequently, even if the leak is developed only in the TFT 106 a,the sub-pixel electrode 103 b driven by the TFT 106 b is unintentionallymade defective.

In other words, there is a problem that even though the pixel divisionmethod in which each pixel electrode includes the assembly of theplurality of sub-pixel electrodes is adopted, a whole pixelunintentionally results in a defective pixel (for example, if the liquidcrystal display uses a normally black mode, the defective pixel isobserved as a full black dot of a whole pixel).

SUMMARY OF THE INVENTION

In order to overcome the problems described above, preferred embodimentsof the present invention provide a liquid crystal display adopting apixel division method by which the size of a defect can be made smallerthan conventional, and also provide a defect correcting method for theliquid crystal display.

According to a preferred embodiment the present invention, a liquidcrystal display is provided with an active matrix array substrateincluding a plurality of gate lines and a plurality of source linesdisposed on a transparent substrate to intersect with each other, and aplurality of pixel electrodes arranged in a matrix, each of the pixelelectrodes including an assembly of a plurality of sub-pixel electrodes,separate active elements respectively connected to the sub-pixelelectrodes in the vicinity of an intersection portion of the gate lineand the source line, the active elements being driven by the common gateline and the common source line, and at least one opening portion beingformed in a lower-layer side line placed in a lower layer at theintersection portion of the gate line and the source line.

In the above liquid crystal display, it is preferable that thelower-layer side line is the gate line, and an upper-layer side linewhich is placed in an upper layer of the lower-layer side line is thesource line.

In addition, in the above liquid crystal display, it is preferable thatan additional source line being partially connected to and extendingalong the source line is further included, or that a bypass line beingconnected to the source line at the intersection portion is included.

In addition, in the above liquid crystal display, it is preferable thatthe opening portion does not include an electrode layer and/or asemiconductor layer.

On the other hand, a defect correcting method for a liquid crystaldisplay according to another preferred embodiment of the presentinvention is a defect correcting method for the above liquid crystaldisplay, and includes at least the steps of cutting the upper-layer sideline passing above the opening portion, and cutting a line including adefective section in the cut line so as to disconnect the defectivesection.

The liquid crystal display as mentioned above is provided with theactive matrix array substrate in which the separate active elements,which are driven by the common gate line and the common source line, arerespectively connected to their corresponding sub-pixel electrodes inthe vicinity of the intersection portion of the gate line and the sourceline, and the opening portion is formed in the lower-layer side line atthe intersection portion of the gate line and the source line.

Therefore, when a defect is developed in any one of the active elementsand the like, the upper-layer side line passing above the openingportion can be easily cut by using a correcting mechanism such as alaser. If a line including the defective section in the cut line is cut,the defective section can be completely isolated from the line.

If correction using an auxiliary line and the like are made as necessarythereafter, the defect can be observed as a defective pixel of asub-pixel, not as a defective pixel of a whole pixel. Thus, the size ofthe defective pixel is made smaller than conventional, leading to nodefects. Consequently, when the active matrix array substrate is usedespecially in a comparatively large liquid crystal display and the like,advantages achieved include an improvement in display quality due to thereduction of the number of defects, an improvement in productionefficiency (yields), and the like.

When the additional source line being partially connected to andextending along the source line is further included, the advantagesdescribed above can be obtained without making the correction using theauxiliary line. Therefore, there is an advantage that hours of workrequired for defect correction can be reduced to further improve theproduction efficiency of the liquid crystal display.

In addition, when the bypass line is connected to the source line in theintersection portion, an aperture area per pixel can be widely assuredwhile maintaining certain redundancy as mentioned above. Therefore,advantages including an improvement in display quality in accordancewith an improvement in display luminance, cost reduction or reduction inpower consumption of a backlight in accordance with an improvement inluminance efficiency, and the like, are achieved.

In addition, when the opening portion does not include the electrodelayer and/or the semiconductor layer, there are advantages that a leakby the electrode layer and a cut piece produced during the line cuttingby using the correcting mechanism such as the laser is not developed,and correction can be easily made.

On the other hand, according to the defect correcting method for theliquid crystal display according to another preferred embodiment of thepresent invention, by cutting the upper-layer side line passing abovethe opening portion, a judgment on whether the defective section ispresent in a line on an input-end side of the cut section or in a lineon an open-end side of the cut section can be easily made through imagedisplay after the line cutting, and the defective section can beisolated from the line by cutting the line including the defectivesection.

Therefore, the defective section, which is conventionally hard to detectby a microscopic observation and the like, can be easily detected. Thus,the defect correcting method has an advantage of allowing for reliablecorrection.

Other features, elements, steps, characteristics and advantages of thepresent invention will become more apparent from the following detaileddescription of preferred embodiments with reference to the attacheddrawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic diagram showing a pixel electrode formed on anactive matrix array substrate provided in a liquid crystal displayaccording to a first preferred embodiment of the present invention.

FIGS. 2A and 2B are schematic diagrams showing a placement relationshipbetween slits formed in the pixel electrode (sub-pixel electrodes) andribs formed on a common electrode in the liquid crystal displayaccording to the first preferred embodiment (in a multi-domain verticalalignment (MVA) mode).

FIGS. 3A and 3B are views showing positions of an SG leak which isdeveloped in thin film transistors (TFTs) on the active matrix arraysubstrate provided in the liquid crystal display according to the firstpreferred embodiment of the present invention.

FIG. 4 is a schematic diagram showing an image observed from atransparent substrate side of the active matrix array substrate when theSG leak shown in FIG. 3 is developed.

FIGS. 5A and 5B are views for explaining steps for making correctionusing an auxiliary line by cutting a source line above an openingportion, and then cutting a source line on an input side or a sourceline on a non-input side to isolate the SG leak.

FIGS. 6A and 6B are schematic diagrams showing images observed from thetransparent substrate side of the active matrix array substrate when thesource line above the opening portion is cut.

FIGS. 7A and 7B are schematic diagrams showing images observed from thetransparent substrate side of the active matrix array substrate when thesource line on the input side or the source line of the non-input sideis cut to isolate the SG leak.

FIGS. 8A and 8B are schematic diagrams showing images observed from thetransparent substrate side of the active matrix array substrate when thecorrection using the auxiliary line is made.

FIG. 9 is a schematic diagram showing a pixel electrode formed on anactive matrix array substrate provided in a liquid crystal displayaccording to a second preferred embodiment of the present invention.

FIGS. 10A and 10B are views for explaining steps of cutting a sourceline above an opening portion, and then cutting a source line on aninput side or a source line on a non-input side to isolate an SG leak inthe liquid crystal display according to the second preferred embodimentof the present invention.

FIG. 11 is a schematic view showing a pixel electrode formed on anactive matrix array substrate provided in a liquid crystal displayaccording to a third preferred embodiment of the present invention.

FIGS. 12A and 12B are views for explaining steps of cutting a sourceline above an opening portion, and then cutting a source line on aninput side or a source line on a non-input side to isolate an SG leak inthe liquid crystal display according to the third preferred embodimentof the present invention.

FIG. 13 is a schematic diagram showing an electrode substrate formed onan active matrix array substrate provided in a conventional liquidcrystal display.

FIG. 14 is a view for explaining a defect correcting method when an SGleak is developed in any one of TFTs in the conventional liquid crystaldisplay.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

A detailed description of a liquid crystal display and a defectcorrecting method for the same according to preferred embodiments of thepresent invention will now be given.

In principle, the liquid crystal display according to preferredembodiments of the present invention is a device in which at least adriving circuit which controls alignment of liquid crystals based on anexternal signal is attached to a liquid crystal panel in which theliquid crystals are sealed in between an active matrix array substratehaving at least a plurality of pixel electrodes and a plurality ofactive elements on a transparent substrate and a substrate having atleast a common electrode for the plurality of pixel electrodes on atransparent common substrate opposed to the transparent substrate, whereinformation can be displayed by conducting optical modulation.

The liquid crystal display is characterized in that the active matrixarray substrate has a new structure. Accordingly, the structure of theactive matrix array substrate provided in the liquid crystal displayaccording to the preferred embodiments of the present invention will bemainly described hereinafter.

On the other hand, the defect correcting method for the liquid crystaldisplay according to a preferred embodiment of the present invention isa method for correcting a defect by utilizing the new structure of theactive matrix array substrate provided in the liquid crystal displayaccording to a preferred embodiment of the present invention. Therefore,the defect correcting method will be described with respect to each ofliquid crystal displays according to preferred embodiments of thepresent invention.

First Preferred Embodiment

FIG. 1 is a schematic diagram showing a pixel electrode formed on anactive matrix array substrate provided in a liquid crystal displayaccording to a first preferred embodiment of the present invention.

On a transparent substrate (unillustrated) constituting the activematrix array substrate 1, a plurality of gate lines 2 extending in a rowdirection are formed, and a plurality of source lines 3 extending in acolumn direction are formed while intersecting at right angles with thegate lines 2 via an insulating layer (unillustrated). Incidentally, thegate line 2 shown in FIG. 1 is the n^(th) one, and the source line 3shown in FIG. 1 is the m^(th) one. In addition, the gate line 2 is alower-layer side line, and the source line 3 is an upper-layer sideline.

A pixel electrode 4 is split into two sub-pixel electrodes 5 a and 5 binterposing the gate line 2 therebetween. In the vicinity of anintersection portion 6 of the gate line 2 and the source line 3,separate thin film transistors (TFTs) 7 a and 7 b which are respectivelyconnected to the sub-pixel electrodes 5 a and 5 b are provided.

The TFTs 7 a and 7 b are on/off controlled by a scanning signal voltageprovided by gate electrodes 8 a and 8 b connected to the common gateline 2. In addition, a display signal voltage provided by sourceelectrodes 9 a and 9 b connected to the common source line 3 is providedto the sub-pixel electrodes 5 a and 5 b via drain lines 11 a and 11 bextending from drain electrodes 10 a and 10 b.

In the drain lines 11 a and 11 b, portions opposed to auxiliarycapacitance lines 12 a and 12 b, which are placed parallel to the gateline 2, via the insulating layer (unillustrated) function as auxiliarycapacitance electrodes 13 a and 13 b. In addition, in the auxiliarycapacitance lines 12 a and 12 b, portions opposed to the auxiliarycapacitance electrode 13 a and 13 b via the insulating layer function asauxiliary capacitance common electrodes 14 a and 14 b.

At the intersection portion 6 of the gate line 2 and the source line 3,at least one opening portion 15 is formed in the gate line 2 being thelower-layer side line. Here, it is preferable that the opening portion15 does not include an electrode layer and/or a semiconductor layer andthe like. In other words, it is preferable that the opening portion 15does not include constituent elements other than the upper-layer sideline.

If the opening portion 15 does not include the electrode layer and/orthe semiconductor layer, a leak and the like by a cut piece and theelectrode layer are hard to be developed at the time of cutting a lineusing a correcting mechanism such as a laser, and correction can beeasily made. Specific examples of the electrode layer and thesemiconductor layer include ITO, an n⁺/i layer and the like for theupper layer.

In the liquid crystal display according to the first preferredembodiment (also in the other preferred embodiments to be describedlater), it is preferable that slits 16 (portions which do not includethe electrode layer) are formed in the sub-pixel electrodes 5 a and 5 b,and ribs 18 are formed on the common electrode 17, as schematicallyshown in FIGS. 2A and 2B, and nematic liquid crystals having negativedielectric anisotropy are used as liquid crystals 19. This is becauseliquid crystal molecules are aligned in multiple directions by theaction of the slits 16 and the ribs 18 at the time of application of anelectric field, so that a favorable wide viewing angle can be obtained.

Next, a defect correcting method for the liquid crystal displayaccording to the first preferred embodiment will be described referringto FIGS. 3A to 8B.

When an SG leak 20 a in the TFT 7 a or an SG leak 20 b in the TFT 7 b isdeveloped between the gate line 2 and the source line 3 as shown inFIGS. 3A and 3B, observation by lighting of a liquid crystal panel showsthat a cross defect 21 having an intersection point at the pixelelectrode 4 is developed in an image viewed from the transparentsubstrate side of the active matrix array substrate 1, as shown in FIG.4. Incidentally, at this point in time, it is uncertain which of the SGleak 20 a in the TFT 7 a or the SG leak 20 b in the TFT 7 b isdeveloped. In other words, it is uncertain which of a state in FIG. 3Aor a state in FIG. 3B is brought about.

Then, as shown in FIGS. 5A and 5B, the source line 3 being theupper-layer side line passing above the opening portion 15 is cut at acut section 22 from the transparent substrate side by using thecorrecting mechanism such as the laser, and the observation by lightingof the liquid crystal panel is made again.

In the observation, if the SG leak 20 a in the TFT 7 a on an input-endside (hereinafter referred to as the “input side”) of the cut section 22of the source line 3 is developed as shown in FIG. 5A, the cross defect21 is still observed as shown in FIG. 6A. On the other hand, if the SGleak 20 b in the TFT 7 b on an open-end side (hereinafter referred to asthe “non-input side”) of the cut section 22 of the source line 3 isdeveloped as shown in FIG. 5B, a line defect 21 a in the direction ofthe gate line 2 disappears and a line defect 21 b in the direction ofthe source line 3 is observed as shown in FIG. 6B.

Shortly, by cutting the source line 3 passing above the opening portion15 at the cut section 22, a judgment on which of the SG leak 20 a in theTFT 7 a or the SG leak 20 b in the TFT 7 b is developed is facilitated.Accordingly, it becomes possible to judge which part of the cut line (asource line 3 a on the input side or a source line 3 b on the non-inputside) is to be cut in the subsequent step.

Then, if the SG leak 20 a in the TFT 7 a is developed as shown in FIG.5A, the source line 3 a on the input side is cut at a cut section 23 ato completely isolate the SG leak 20 a from the source line 3. In thiscase, in the image of the observation by lighting, the line defect 21 ain the direction of the gate line 2 disappears, and the line defect 21 bin the direction of the source line 3 is observed, as shown in FIG. 7A.

On the other hand, if the SG leak 20 b in the TFT 7 b is developed asshown in FIG. 5B, the source line 3 b on the non-input side is cut at acut section 23 b to completely isolate the SG leak 20 b from the sourceline 3. In this case, in the image of the observation by lighting, theline defect 21 b in the direction of the source line 3 is still observedas shown in FIG. 7B.

Next, in a case where the SG leak 20 a in the TFT 7 a is developed asshown in FIG. 5A, by making correction using an auxiliary line (aredundancy line) (unillustrated) and inputting a source signal S′ viathe auxiliary line from the source line 3 b on the non-input side to theTFT 7 b, a sub-pixel (the sub-pixel electrode 5 b) can be driven. On theother hand, in a case where the SG leak 20 b in the TFT 7 b is developedas shown in FIG. 5B, by performing the correction using the auxiliaryline and inputting the source signal S′ (unillustrated) from the sourceline 3 b on the non-input side, sub-pixels (pixels) (unillustrated)arranged on the non-input side of the sub-pixel (the sub-pixel electrode5 b) can be driven.

Therefore, for example, if the liquid crystal display according to thefirst preferred embodiment uses a normally black mode, the defectivepixel is observed as not a full black dot of a whole pixel but a halfblack dot 24 a or 24 b of a sub-pixel as shown in FIGS. 8A and 8B. Inaddition, for example, if the liquid crystal display according to thefirst preferred embodiment uses a normally white mode, the defectivepixel is observed as a half bright dot of a sub-pixel, and by performingprocessing such as forming it into a black dot, the defective pixel isobserved as a half black dot 24 a or 24 b of a sub-pixel. In eithercase, the size of the defective pixel is made smaller than conventional,leading to a state of no defect (a normal level in view of displayquality can be attained), so that quality of the liquid crystal displayis improved.

For the correction using the auxiliary line, a known method can be used(see, for example, Japanese Patent Application Unexamined PublicationNos. Hei5-203986 and Hei9-146121).

Specifically, an auxiliary line (unillustrated) is placed in aperipheral portion of a display region on the active matrix arraysubstrate 1 so as to extend completely around or extend half-way aroundthe display region, and an input end and an open end of the source line3 are short-circuited by the auxiliary line.

Second Preferred Embodiment

FIG. 9 is a schematic view showing a pixel electrode formed on an activematrix array substrate provided in a liquid crystal display according toa second preferred embodiment of the present invention.

The structure of the active matrix array substrate 30 provided in theliquid crystal display according to the second preferred embodiment isbasically the same as the structure of the active matrix array substrate1 provided in the liquid crystal display according to the firstpreferred embodiment except for the source line 3. Therefore,differences from the liquid crystal display and the defect correctingmethod for the same according to the first preferred embodiment will bemainly described hereinafter.

As shown in FIG. 9, in the active matrix array substrate 30 provided inthe liquid crystal display according to the second preferred embodiment,an additional source line 32 is further included while being partiallyconnected to the source line 3 via connecting portions 31 and extendingalong the source line 3.

In the liquid crystal display according to the second preferredembodiment as mentioned above, when the SG leak 20 a in the TFT 7 a orthe SG leak 20 b in the TFT 7 b is developed as shown in FIGS. 10A and10B, similarly to the first preferred embodiment, the source line 3being the upper-layer side line passing above the opening portion 15 iscut at the cut section 22 from the transparent substrate side by usingthe correcting mechanism such as the laser for correcting the SG leak 20a or the SG leak 20 b.

Accordingly, a judgment on which of the SG leak 20 a in the TFT 7 a orthe SG leak 20 b in the TFT 7 b is developed can be easily made based onan image viewed from the transparent substrate side. Then, if the SGleak 20 a in the TFT 7 a is developed as shown in FIG. 10A, the sourceline 3 a on the input side is cut at the cut section 23 a to completelyisolate the SG leak 20 a from the source line 3.

Here, as the active matrix array substrate 30 provided in the liquidcrystal display according to the second preferred embodiment has theadditional source line 32, a source signal S from the input side isinputted to the TFT 7 b via the additional source line 32. Accordingly,the sub-pixel (the sub-pixel electrode 5 b) can be driven without makingthe correction using the auxiliary line.

On the other hand, if the SG leak 20 b in the TFT 7 b is developed asshown in FIG. 10B, the source line 3 b on the non-input side is cut tocompletely isolate the SG leak 20 b from the source line 3.

Accordingly, the source signal S from the input side is supplied also tothe non-input side via the additional source line 32. Thus, thesub-pixels (pixels) placed on the non-input side of the sub-pixel (thesub-pixel electrode 5 b) can be driven without making the correctionusing the auxiliary line.

Consequently, also owing to the liquid crystal display according to thesecond preferred embodiment, the defect can be observed as a defectivepixel of a sub-pixel, not as a defective pixel of a whole pixel, and thesize of the defective pixel is made smaller than conventional, leadingto no defects.

In addition, in the liquid crystal display according to the secondpreferred embodiment, there is no need to make the correction using theauxiliary line. As a result, hours of work required for defectcorrection can be reduced to improve production efficiency of the liquidcrystal display. Further, delay of the source signal due to thecorrection using the auxiliary line and the like in the case of a largeliquid crystal display can be avoided.

Third Preferred Embodiment

FIG. 11 is a schematic diagram showing a pixel electrode formed on anactive matrix array substrate provided in a liquid crystal displayaccording to the third preferred embodiment.

The structure of the active matrix array substrate 40 provided in theliquid crystal display according to the third preferred embodiment isalso basically the same as the structure of the active matrix arraysubstrate 1 provided in the liquid crystal display according to thefirst preferred embodiment except for the source line 3. Therefore,differences from the liquid crystal display and the defect correctingmethod for the same according to the first preferred embodiment will bemainly described hereinafter.

As shown in FIG. 11, in the active matrix array substrate 40 provided inthe liquid crystal display according to the third preferred embodiment,a bypass line 41 is included in the vicinity of the opening portion 15of the source line 3. In this preferred embodiment, an example of thispreferred embodiment where the bypass line 41 does not pass above theopening portion 15 is illustrated. However, the bypass line 41 may passabove the opening portion 15.

In the liquid crystal display according to the third preferredembodiment as mentioned above, when the SG leak 20 a in the TFT 7 a orthe SG leak 20 b in the TFT 7 b is developed as shown in FIGS. 12A and12B, similarly to the first and second preferred embodiments, the sourceline 3 being the upper-layer side line passing above the opening portion15 is cut at the cut section 22 from the transparent substrate side byusing the correcting mechanism such as the laser for correcting the SGleak 20 a or the SG leak 20 b.

Accordingly, a judgment on which of the SG leak 20 a in the TFT 7 a orthe SG leak 20 b in the TFT 7 b is developed can be easily made based onan image viewed from the transparent substrate side. Thereafter, if theSG leak 20 a in the TFT 7 a is developed as shown in FIG. 12A, thesource line 3 a on the input side is cut at the cut section 23 a tocompletely isolate the SG leak 20 a from the source line 3.

Here, as the active matrix array substrate 40 provided in the liquidcrystal display according to the third preferred embodiment has thebypass line 41, the source signal S from the input side is inputted tothe TFT 7 b via the bypass line 41. Accordingly, the sub-pixel (thesub-pixel electrode 5 b) can be driven without making the correctionusing the auxiliary line.

On the other hand, if the SG leak 20 b in the TFT 7 b is developed asshown in FIG. 12B, the source line 3 b on the non-input side is cut tocompletely isolate the SG leak 20 b from the source line 3.

Thus, the source signal S from the input side is supplied also to thenon-input side via the bypass line 41. Accordingly, the sub-pixels(pixels) placed on the non-input side of the sub-pixel (the sub-pixelelectrode 5 b) can be driven without making the correction using theauxiliary line.

Consequently, also according to the liquid crystal display according tothe third preferred embodiment, the defect can be observed as adefective pixel of a sub-pixel, not as a defective pixel of a wholepixel, and the size of the defective pixel is made smaller thanconventional, leading to no defects. In addition, the liquid crystaldisplay according to the third preferred embodiment has equal redundancyto the liquid crystal display according to the second preferredembodiment.

Further, in the liquid crystal display according to the third preferredembodiment, an aperture area per pixel can be widely assured, whichenables an improvement in display quality in accordance with animprovement in display luminance, cost reduction or reduction in powerconsumption of a backlight in accordance with an improvement inluminance efficiency, and the like.

The foregoing descriptions of the preferred embodiments of the presentinvention are not intended to be exhaustive or to limit the presentinvention to the precise form disclosed, and modifications andvariations are possible in the light of the above teachings or may beacquired from practice of the present invention.

While the descriptions have been made to cases where each of the pixelelectrodes includes the assembly of two sub-pixel electrodes in theabove-described preferred embodiments, it is also preferable that eachof the pixel electrodes includes an assembly of three or more sub-pixelelectrodes.

In addition, while the descriptions have been made with reference toexamples of preferred embodiments where the gate line is the lower-layerside line and the source line is the upper-layer side line, it is alsopreferable that the gate line is the upper-layer side line and thesource line is the lower-layer side line.

Incidentally, while the descriptions have been made of examples ofpreferred embodiments where the TFTs are preferably used as the activeelements, any elements which function as a switching element such as ametal insulator metal (MIM) may be used.

While preferred embodiments of the present invention have been describedabove, it is to be understood that variations and modifications will beapparent to those skilled in the art without departing the scope andspirit of the present invention. The scope of the present invention,therefore, is to be determined solely by the following claims.

1. A liquid crystal display provided with an active matrix arraysubstrate, the active matrix array substrate comprising: a plurality ofgate lines extending in a first direction and a plurality of sourcelines extending in a second direction that is different from the firstdirection, the plurality of gate lines and the plurality of source linesbeing arranged on a transparent substrate so as to intersect with eachother at a plurality of intersection portions; a plurality of pixelelectrodes arranged in a matrix; and at least one of the plurality ofsource lines includes at least one loop arranged to define an openingportion located at or adjacent to one of the plurality of intersectionportions; wherein at least one portion of at least one of the pluralityof gate lines is located within the opening portion and extends in thefirst direction; and at least one portion of a source electrode extendsout from the at least one loop to overlap with another portion of the atleast one of the plurality of gate lines.
 2. The liquid crystal displayaccording to claim 1, wherein the at least one loop includes only oneloop defined in the at least one of the plurality of source lines. 3.The liquid crystal display according to claim 1, wherein the at leastone loop includes a plurality of loops defined in the at least one ofthe plurality of source lines.
 4. The liquid crystal display accordingto claim 1, wherein each of the plurality of source lines includes theat least one loop defined therein.
 5. The liquid crystal displayaccording to claim 4, wherein the at least one loop includes only oneloop defined in each of the plurality of source lines.
 6. The liquidcrystal display according to claim 4, wherein the at least one loopincludes a plurality of loops defined in each of the plurality of sourcelines.
 7. The liquid crystal display according to claim 1, wherein anadditional source line is partially connected to and extends along theat least one of the plurality of source lines.
 8. The liquid crystaldisplay according to claim 1, further comprising a bypass line connectedto the at least one of the plurality of source lines at one of theplurality of intersection portions.
 9. The liquid crystal displayaccording to claim 1, wherein the at least one loop is arranged tooverlap with at least one opening portion defined in one of theplurality of gate lines, the at least one opening portion defined in theone of the plurality of gate lines does not contain at least one of anelectrode layer and a semiconductor layer.
 10. The liquid crystaldisplay according to claim 9, wherein the electrode layer defines apixel electrode.
 11. The liquid crystal display according to claim 9,wherein the at least one portion of the source electrode projects in thefirst direction from the at least one loop to an end point locatedbeyond and outside of the at least one opening portion defined in theone of the plurality of gate lines.
 12. The liquid crystal displayaccording to claim 9, wherein the at least one portion of the sourceelectrode projects in the first direction from the at least one loop toan end point of the at least one opening portion defined in the one ofthe plurality of gate lines.
 13. The liquid crystal display according toclaim 1, wherein the at least one portion of the source electrodeprojects in the first direction from the at least one loop to a locationwhere a drain electrode is located.
 14. The liquid crystal displayaccording to claim 9, wherein the at least one opening portion definedin the one of the plurality of gate lines extends in the first directionfrom the at least one portion of the at least one of the plurality ofsource lines along the at least one of the plurality of gate lines. 15.The liquid crystal display according to claim 9, wherein the at leastone portion of the at least one of the plurality of source lines extendsthrough an approximate center of the at least one opening portiondefined in the one of the plurality of gate lines.
 16. The liquidcrystal display according to claim 9, wherein the at least one openingportion defined in the one of the plurality of gate lines is surroundedby an edge of the one of the plurality of gate lines.
 17. The liquidcrystal display according to claim 1, further comprising a drainelectrode and a storage capacitor electrode connected to each other. 18.The liquid crystal display according to claim 17, wherein the storagecapacitor electrode is provided on a segment that protrudes from anauxiliary capacitance line.
 19. The liquid crystal display according toclaim 1, further comprising a gate electrode extending from the at leastone of the plurality of gate lines, wherein the gate electrode and aportion of the at least one loop overlap each other.
 20. The liquidcrystal display according to claim 1, further comprising a gateelectrode extending from the at least one of the plurality of gatelines, wherein the gate electrode and a portion of the source electrodeoverlap each other.